Endocrine Abstracts

Background: Acquired male secondary hypogonadism is a relatively common cause of referral to the endocrine clinic. However, the extent to which further investigation is required, and the indications for a trial of testosterone therapy, remain unclear. Aim To review the clinical/biochemical/radiological findings in men presenting with this condition.

Methods: We performed a retrospective case analysis of 41 consecutive patients referred to our clinic over a 30 month period with symptoms/signs of androgen insufficiency and a provisional diagnosis of acquired isolated secondary hypogonadism.

Results: The age of the cohort ranged from 17–71 years (13/41 <40 years). Duration of symptoms varied widely (6 months to 10 years). 12/41 and 10/41 patients had depression and diabetes mellitus respectively. 18 were obese and 11 were overweight. Testicular volumes <15 mL were noted in five cases, and gynaecomastia in four patients. Based on serum total testosterone levels (08:00–10:00 h), 7/41 patients had apparent severe hypogonadism (<5.2 nmol/l), 28/41 had mild-moderate hypogonadism (5.2–8.0 nmol/l) and 6/41 had ‘low-normal’ levels (8.0–11.5 nmol/l) (RR 8–29). However, calculated free testosterone (Vermeulen) was found to be low in only 7/34, consonant with the majority of the cohort having low SHBG levels (median 20.6 nmol/l, IQR 12.2–27.2, RR 10–57). Mild hyperprolactinaemia (prolactin <100 mU/L above RR), was observed in three patients, but no other endocrinopathy was detected in the cohort as a whole. Pituitary microadenomas (3–6 mm diameter) were found in three patients. 8/32 had evidence of osteoporosis, only one of whom had a low free testosterone level.

Conclusions: Most males referred with apparent acquired isolated central hypogonadism had normal calculated free testosterone levels, no associated endocrinopathy, and normal pituitary imaging, indicating a low yield with respect to further ‘pituitary investigation’ in this cohort. However, a surprisingly high rate of osteoporosis was observed.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.